SURVIVAL AND GROWTH OF NEWLY TRANSFORMED LAMPSILIS CARDIUM AND L. SILIQUOIDEA, IN A FLOW THROUGH, CONTINUOUS FEEDING TEST SYSTEM

Jeffery R. Meinertz, Theresa M. Schreier, Karina R. Hess, and Michelle R. Bartsch
USGS

Upper Midwest Environmental Sciences Center
2630 Fanta Reed Road
La Crosse, WI 54603
jmeinertz@usgs.gov

This work was conducted as part of the project, "Demonstration of an approach to assess the impact of emerging contaminants on aquatic invertebrates in national parks: A project for the St. Croix National Scenic Riverway", and was funded, in part, by the USGS National Resources Preservation Program. The objectives of the overriding project included (1) determining the occurrence and concentration of emerging contaminants, pharmaceuticals and personal care products (PPCP), in water and bottom sediments in the St. Croix National Scenic Riverway (Riverway), (2) evaluating the effects of selected PPCP found in the Riverway on Daphnia with chronic toxicity trials, and (3) evaluating the effects of selected PPCP on juvenile freshwater mussels with chronic laboratory toxicity tests. Pharmaceuticals and personal care products are a group of compounds that include prescription and over-the-counter drugs, detergent by-products, fragrances, and cosmetics. These compounds are continually introduced into the aquatic environment largely through wastewater treatment plants. Many PPCP have been documented in streams throughout the U.S. (Kolpin et al. 2002) with some PPCP being found in the Riverway's water and sediment.

The third objective was perceived to be the biggest challenge for the project, primarily because conducting chronic (28-day) toxicity trials with juvenile or newly transformed mussels was unprecedented. Before chronic toxicity trials could be initiated, a test system had to be developed that could provide suitable mussel survival and reproducibility in control groups.

A test system was constructed with guidance given in American Society for Testing and Materials Designation E 2455 05 (ASTM 2005). Largemouth bass (Micropterus salmoides) were infested with glochidia from fat mucket (Lampsilis siliquoidea) and plain pocketbook mussels (L. cardium). One day after transformation, mussels were transferred (40 per chamber) to test chambers (250 mL beakers, water volume, 200 mL) each containing a 4-mm layer of silica sand. The test system held 60 chambers, 30 chambers with L. siliquoidea and 30 with L. cardium. The 30 chambers assigned to a species were separated into 5 blocks of 6 chambers (each block in a 2 x 3 configuration) with each chamber in a block receiving 1 of the following 6 food types prepared with concentrated algal products: (1) Nannochloropsis (2) Nannochloropsis and Tetraselmis, (3) Nannochloropsis, Tetraselmis, and Chlorella, (4) Nannochloropsis and Thalassiorsira weissflogii, (5) Nannochloropsis and Pavlova and (6) Nannochloropsis, Thalassiorsira weissflogii, and Pavlova. After 28 days of continuous feeding in the flow through system, chambers were surveyed for live mussels. Only live mussels were retained for growth measurements. For L. siliquoidea, mean survival for each food type ranged from 35% (food type 6) to 81% (food type 3). For L. cardium, mean survival for each food type ranged from 12% (food type 5) to 66% (food type 1). Growth data are being summarized. The preliminary data indicate that L. siliquoidea may be a suitable species for conducting 28-day toxicity trials with PPCP if continuously fed a diet of Nannochloropsis, Tetraselmis, and Chlorella.

References

American Standards for Testing and Materials Designation E 2455-05 (ASTM). 2005. Standard guide for conducting laboratory toxicity tests with freshwater mussels. ASTM International, West Conshokocken, Pennsylvania.

Kolpin, D.W., E.T. Furlong, M.T. Meyer, E.M. Thurman, S.D. Zaugg, L.B. Barber, and H.T. Buxton. 2002. Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999-2000: A national reconnaissance. Environmental Science and Technology, 36:1202-1211.